In Japan, the Working Environment Measurement Standards require employers to measure noise of working environment by two kinds of methods using a sound level meter (SLM) once every 6 months. A-Sampling method is to be measured equivalent continuous sound level for at least 10 min. B-Sampling method is to be performed close to workers at times when the sound level appeared highest. We perform the risk assessment based on the values of the field measurement. In the East Japan Railway Company, workers move around several workshops and use hand tools. Therefore, it is difficult to estimate the personal noise exposure using only an SLM. To compare dose measurement with the Japanese field measurement, we carried out dose measurements for inspection or repair workers using a Personal Noise Dose Meter (Type 4448; Brüel & Kjær). The results revealed that all sound levels using a dosimeter were less than 85 dBA, while the sound levels using an SLM were more than 90 dBA. In this case, the risk can be overestimated. Thus, we conclude that the Working Environment Measurement Standards should adopt the dose measurement.